Python Classes and Objects

Python is an object oriented programming language.

In Python almost everything has its properties and methods as an object.

A Class or a "blueprint" to generating objects is like a constructor.

Use the term class to build a class :

Example :- Create a class called MyClass that contains the property x :

class MyClass:
  x = 5
print(MyClass)

Output :-

Now we can make objects using the MyClass class:

Example :- Create the p1 name object and print the x value :

class MyClass:
  x = 5
p1 = MyClass()
print(p1.x)

Output :-

The previous examples are the most simplistic classes and objects and are not very suitable for applications of real life.

We must comprehend the __init__() built-in function for understanding the meaning of classes.

Every class has a function named __init__(), which always is performed when you start the class.

Use the function __init__() to assign object property values or other essential activities to do while creating the object :

Example :- Use the __init__() function to allocate values for name and age to create a class called the person :

class Person:
  def __init__(self, name, age):
    self.name = name
    self.age = age
p1 = Person("John", 36)
print(p1.name)
print(p1.age)

Output :-

Note : Whenever a class is used to create a new object, __init__() is automatically invoked.

Objects may have methods as well. Object methods are functions that are part of the object.

Let us in Person Class build a method :

Example :- Insert a feature which prints a welcome and execute it on the object p1 :

class Person:
  def __init__(self, name, age):
    self.name = name
    self.age = age
  def myfunc(self):
    print("Hello my name is " + self.name)
p1 = Person("John", 36)
p1.myfunc()

Output :-

Note : The Self is a reference to the current class instance and is used to access class variables.

The self parameter refers to the current class instance and is used to access class-related variables.

It doesn't need to be called self, but it must be the primary parameter for any function in the class :

Example :- Instead of self use the terms mysillyobject or abc :

class Person:
  def __init__(mysillyobject, name, age):
    mysillyobject.name = name
    mysillyobject.age = age
  def myfunc(abc):
    print("Hello my name is " + abc.name)
p1 = Person("John", 36)
p1.myfunc()

Output :-

You can change objects such like this :

Example :-

Set the age of p1 to 40 :

class Person:
  def __init__(self, name, age):
    self.name = name
    self.age = age
  def myfunc(self):
    print("Hello my name is " + self.name)
p1 = Person("John", 36)
p1.age = 40
print(p1.age)

Output :-

The del keyword allows you to remove property on objects :

Example :- Delete the object p1 from age property :

class Person:
  def __init__(self, name, age):
    self.name = name
    self.age = age
  def myfunc(self):
    print("Hello my name is " + self.name)
p1 = Person("John", 36)
del p1
print(p1)

Output :-

By employing del keyword, you can remove items.

Example :- Delete the p1 object :

class Person:
  def __init__(self, name, age):
    self.name = name
    self.age = age
  def myfunc(self):
    print("Hello my name is " + self.name)
p1 = Person("John", 36)
del p1
print(p1)

Output :-

class definitions may not be empty, but if you have a class definition without content for any reason, please use the pass declaration to prevent an error.

Example :- class Person :

class Person:
  pass
# having an empty class definition like this, would raise an error without the pass statement